Blade servers deal with great amounts of data. The so-called “Server Blade” refers to an entire server designed to fit on a small plug-and-play card. Several blade servers can be installed in one rack, sharing the same power supplies, monitor, keyboard and other electronic components while offering potentially easier maintenance. However, large operating space is always needed to lock or unlock the blade servers. Therefore, sliding apparatus and casing using the sliding apparatus that can save operating space would be beneficial.